1. Field of the Invention
The present invention is related to a vehicular monitoring system with a multi-window display, and more particularly to a multi-window monitoring system that can help vehicle drivers monitor changing conditions in usual blind spots around the vehicle using multiple video cameras and ultrasonic signal transceivers.
2. Description of Related Art
Currently back-up detectors are becoming standard equipment in most passenger vehicles. The back-up detector is used to check the distance between the vehicle and any object behind the vehicle when the vehicle is in the reverse gear. The electronic detector has an array of ultrasonic sensors on the bumper which is connected to the gear box control circuitry and an alarm. When the vehicle is in the reverse gear and an object appears in the preset warning range, the electronic detector will initiate the alarm to warn the vehicle driver. Therefore, this is an effective safety feature for passenger vehicles.
However, nothing is more realistic than seeing video images that actually present the road conditions. Modern drivers have become satisfied with only electronic detectors. They need an all-purpose monitoring device that allows them to see images taken from different angles simultaneously, especially in usual blind spots where the driver's view is blocked by the vehicle body. With such a monitoring device, the driver's visibility is greatly enhanced because the driver is more aware of the changing conditions around the vehicle.
Also, conventional back-up detectors mounted on a vehicle with elevated bumpers cannot detect objects lying below the detection zone, but these objects do pose a real threat. If the vehicle runs over them unwarily, they can cause damage to the bottom of the vehicle.
To correct, the foregoing problem, some manufacturers have incorporated a video camera and a display monitor in the detection systems. The monitor is either installed in the rearview mirror or as a stand-alone display on the dashboard in the driver compartment, such that images from the video cameras at the rear of the vehicle are simultaneously presented at the rearview mirror or stand-alone monitor during normal driving and parking. However, the present design of these detection systems with video display are only suitable for passenger vehicles, and the detection systems have only one video camera.
Large vehicles, The shape and size of vehicle bodies of large vehicles cause large vehicles to have more blind spots than a passenger car. Consequently, using one video camera to cover all possible angles is almost impossible. Furthermore, simultaneously displaying the video from several video cameras presents a significant techical problem. Some of the common problems for different types of detector systems are described below.
1. Hard-wired detector systems: Using several hard-wired detectors and video cameras creates complicated wiring configurations and raises the question of how to control multiple images from several video cameras on a common screen simultaneously.
2. Wireless detector systems: these detectors do away with much of the electrical wiring, but in the case where several video cameras use the same frequency band or nearby vehicles have wireless detectors with similar frequency bands, video degradation will occur due to mutual interference.
The foregoing problems associated with the use of multiple video cameras need to be solved if simultaneous operation is to be achieved.